Super-Photons Used For Good, Not Evil

Super-photons may be able to provide a way to encode yet more information on CDs; more powerful computers and higher data security may also be possible. This is not your father's Thessian super-proton technology.

University of Toronto quantum optics researcher Morgan Mitchel has been entangling photons (light conceived of as small packets of energy). At the quantum level, a phenomenon called "entanglement" is observed, in which two or more particles become linked in such a way that any action that affects one affects all the others - no matter what the distance between them. This phenomenon can cause a set of multiple photons to behave as if they were one. Three photons could behave as a single photon, but with three times the energy.

"It looks like a super-photon," said Mitchell. "For this experiment, the hardest part was making them indistinguishable, which means not just putting them in the same location, but making sure they're there at the same time, that they are the same color, and going in the same direction. You have to guarantee all of these (aspects) at once."

So how can a super-photon result in greater density of data storage? CDs store data in patterns of tiny pits about a half-micron wide. The problem with CDs is that the smallest size pit that can be used is dependent on the wavelength of light that is used to see it (the diffraction limit). By entangling photons, a super-photon with three times the energy can beat the diffraction limit, giving resolution that is three times better. Better resolution means that the pits can be smaller and closer together, resulting in more storage.

The science fiction reference to the Thessians comes from John W. Campbell's 1932 novel Invaders From The Infinite, in which the evil Thessians make use of a mysterious ray that effortlessly slices through the all but invulnerable cosmium shielding of ships. The scientist-heroes of the book offer the following analysis:

"It's a super-photon. What they do is use a field somewhat similar to the field we use in making cosmium, except that in theirs, instead of the photons lying side by side, they slide into one another, compounding. They evidently get three photons to go into one." (More)